A number of processing steps in ceramic manufacturing result in the emission of hazardous air pollutants (HAPs) such as acid gases (e.g., hydrofluoric acid, HF; and hydrochloric acid, HCl) that are released in the high-temperature firing steps of the manufacturing process. Table 1 provides estimates of the emission factor ratings for the HAPs emitted during the firing steps in ceramic products manufacturing.1
In September 2015, the U.S. Environmental Protection Agency (EPA) issued a final rule for the National Emission Standard for Hazardous Air Pollutants (NESHAP) for Brick and Structural Clay Products (BSCP) and Clay Ceramics Manufacturing.2 The rule for clay ceramics applies to major HAP sources manufacturing vitreous plumbing fixtures (sanitaryware), including sinks, toilets, and pressed floor and wall tile. The new regulation limits the total emissions of HF, HCl and chlorine (Cl2) to 140 lb/hr (HCl equivalent), where the limit applies to the sum of emissions from all kilns within a facility. Under the final Clay Ceramic NESHAP, HF and HCl emissions must be continuously monitored using one of the following: EPA Method 26A, EPA Method 26, EPA Method 320 or any other method approved under 40 CFR 63.7(f) of the EPA’s General Provisions.